Smithsonian - National Museum of American History, Behring Center

Physical Sciences Collection - Surveying and Geodesy

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Theodolite - click to enlarge

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Catalogue number:

"Heinrich Wild Heerbrugg No. 218"

height 9.5 inches

The "Universal Theodolite" that Heinrich Wild introduced in 1923, later known as the T2, incorporated a radically new design. It was also highly successful -- about 100,000 of these instruments were eventually produced. Wild Heerbrugg, Inc. gave this example to the Smithsonian in 1961, stating that it had had been delivered on April 12, 1924, and used until July 1960 in the Swiss Canton of Tessin. The serial number probably means that this is the 18th instrument of this sort made for the market.

This instrument has a steel frame, and weighs only 9.5 pounds. The horizontal and vertical circles are glass, and read directly to single seconds. The telescope magnifies 24 times and, being equipped with stadia wires, can be used for tachymetry. An auxiliary eyepiece lying alongside the telescope allows the user to read either circle without moving away from the station. By a combination of internal optics, each reading gives the mean of 2 opposite points on the circles.

Ref: Henry Wild's Universal Theodolite (Heerbrugg, ca. 1925).

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